Liquid crystal composition with positive dielectric anisotropy and liquid crystal display thereof

Abstract

The invention relates to a liquid crystal composition with positive dielectric anisotropy and a liquid crystal display thereof, and belongs to the technical field of liquid crystal materials. The liquid crystal composition comprises at least one compound with a structure as shown in a general formula I, at least one compound with a structure as shown in a general formula II, at least one compound with a structure as shown in a general formula III, at least one compound with a structure as shown in a general formula IV, at least one compound with a structure as shown in a general formula III, at least one compound with a structure as shown in a general formula III, at least one compound with a structure as shown in a general formula III, at least one compound with a structure as shown in a general formula III, at least one compound with a structure as shown in a general formula III, at least one compound with a structure as shown in a general formula III, and at least one compound with a structure as shown in a general formula III, the mass percent of the compound is 25%-75%: # imgabs3 #, the mass percent of the compound is 3%-30%: # imgabs4 #. The liquid crystal composition disclosed by the invention is beneficial to reducing the driving voltage of a liquid crystal display, so that the liquid crystal display is more energy-saving; meanwhile, the composition has a relatively large ratio of epsilon perpendicular to / delta epsilon, so that the transmittance of a liquid crystal display can be improved.

Description

Technical Field

[0001] The present invention relates to a liquid crystal composition having positive dielectric anisotropy and a liquid crystal display using the same, and belongs to the technical field of liquid crystal materials. Background Art

[0002] With the progress of display technology and the improvement of people's living standards, people have higher requirements for display quality and display experience. At the same time, in order to meet the requirements of environmental protection in modern society, it is very necessary to reduce power consumption and save electricity.

[0003] If a liquid crystal display is to reduce power consumption, the liquid crystal material used should have a lower threshold voltage to achieve the purpose of low-voltage driving and reducing power consumption. This requires the liquid crystal material to have a larger dielectric anisotropy and an appropriate optical anisotropy. According to the transmittance formula of the IPS mode, transmittance ∝ ε⊥ / Δε (∝ represents a proportional relationship). A large ε⊥ / Δε ratio is beneficial to improving the light transmittance. High light transmittance can reduce the backlight intensity of the liquid crystal display, thereby achieving the purpose of saving energy consumption and extending the service life of the device.

[0004] In practical applications, it is impossible to meet the above conditions with a single compound. Therefore, it is usually achieved by combining several compounds, and the selection and ratio of different liquid crystal compounds directly affect the performance of the liquid crystal material. The liquid crystal composition with positive dielectric anisotropy provided in this application is applicable to displays in the TN mode, FFS mode, and IPS mode. It has a large positive dielectric anisotropy and a low threshold voltage, which can enable the liquid crystal display to achieve low-voltage driving, making it more energy-saving. At the same time, this composition also has a large ε⊥ / Δε ratio, which is beneficial to improving the transmittance of the liquid crystal display. Summary of the Invention

[0005] With the progress of display technology and the improvement of people's living standards, people have higher requirements for display quality and display experience. At the same time, in order to meet the requirements of environmental protection in modern society, it is very necessary to reduce power consumption and save electricity. The liquid crystal composition with positive dielectric anisotropy provided by the present invention can enable the liquid crystal display to achieve low-voltage driving and be more energy-saving; at the same time, it is also beneficial to improve the transmittance of the liquid crystal display.

[0006] The liquid crystal composition of the present invention comprises one or more compounds represented by Structural General Formula I, Structural General Formula II, Structural General Formula III, Structural General Formula IV, and Structural General Formula V. The liquid crystal composition of the present invention having positive dielectric anisotropy can improve the ratio of ε⊥ / Δε by adding the compound represented by Structural General Formula I, thereby improving the transmittance of the liquid crystal display; this liquid crystal composition has a relatively high clearing point, appropriate optical anisotropy, large positive dielectric anisotropy, low threshold voltage, and a large ε⊥ / Δε ratio, and can be applied to TN mode, FFS mode, and IPS mode displays. The large positive dielectric anisotropy and low threshold voltage are beneficial to reducing the driving voltage of the liquid crystal display, thereby making it more energy-efficient; the large ε⊥ / Δε ratio is beneficial to improving the transmittance of the liquid crystal display.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A liquid crystal composition having positive dielectric anisotropy, by mass percentage, comprises the following components:

[0009] (1) Compounds containing at least one or more structures represented by General Formula I, with a mass fraction of 1% - 15%. The structural general formula of General Formula I is:

[0010]

[0011] In the above formula, R 1 represents an alkyl group of C 1 ~C 7 or an alkoxy group of C 1 ~C 7 ;

[0012] (2) Compounds containing at least one or more structures represented by General Formula II, with a mass fraction of 5% - 28%. The structural general formula of General Formula II is:

[0013]

[0014] In the above formula, R 2 represents an alkyl group of C 1 ~C 7 or an alkoxy group of C 1 ~C 7 ;

[0015] n 1 represents 0 or 1;

[0016] Ring Ring and Ring are the same or different and each independently represents: One or more H on the benzene ring can be replaced by F;

[0017] (3) The composition contains at least one or more compounds with the structure shown in General Formula Ⅲ, with a mass fraction of 3% - 28%. The general formula of General Formula Ⅲ is:

[0018]

[0019] In the above formula, R 3 represents an alkyl group of C 1 ~C 7 , an alkoxy group of C 1 ~C 7 , or a straight-chain alkenyl group of C 2 ~C 7 ;

[0020] X 1 , X 2 are the same or different, and each independently represents -H or -F;

[0021] (4) The composition contains at least one or more compounds with the structure shown in General Formula Ⅳ, with a mass percentage of 25% - 75%. The general formula of General Formula Ⅳ is:

[0022]

[0023] In the above formula, R 4 , R 5 each independently represents a straight-chain alkyl group of C 1 ~C 7 , a straight-chain alkoxy group of C 1 ~C 7 , a straight-chain alkenyl group of C 2 ~C 7 , or -F;

[0024] X 3 , X 4 are the same or different, and each independently represents -H, -F;

[0025] Ring and Ring are the same or different, and each independently represents: One or more H on the benzene ring can be replaced by F;

[0026] (5) The composition contains at least one or more compounds with the structure shown in General Formula Ⅴ, with a mass percentage of 3% - 30%. The general formula of General Formula Ⅴ is:

[0027]

[0028] In the above formula, R 6 , R 7 each independently represents a straight-chain alkyl group of C 1 ~C 7 and a straight-chain alkyl group of C1 ~C 7 linear alkoxy group of C 2 ~C 7 linear alkenyl group of C or -F;

[0029] ring represents: One or more H on the benzene ring can be replaced by F.

[0030] The sum of the masses of the compounds shown in General Formula I, General Formula II, General Formula III, General Formula IV and General Formula V is 100%.

[0031] Preferably, the compound shown in General Formula I is selected from one or more of the following compounds I-1 to I-4:

[0032]

[0033]

[0034] More preferably, the compound shown in General Formula I is Compound I-2.

[0035] In the liquid crystal composition having positive dielectric anisotropy, the mass percentage of the compound of General Formula I is 1% to 15%, preferably 1% to 13%, and more preferably 1% to 12%.

[0036] Preferably, the compound shown in General Formula II is selected from one or more of the following compounds II-1 to II-12:

[0037]

[0038]

[0039] More preferably, the compound shown in General Formula II is selected from one or more of Compounds II-6, II-10 and II-11.

[0040] In the liquid crystal composition having positive dielectric anisotropy, the mass percentage of the compound of General Formula II is 5% to 28%, preferably 7% to 25%, and more preferably 8% to 23%.

[0041] Preferably, the compound shown in General Formula III is selected from one or more of the following compounds III-1 to III-8:

[0042]

[0043]

[0044] More preferably, the compound shown in General Formula III is selected from one or two of Compounds III-6 and III-8.

[0045] In the liquid crystal composition having positive dielectric anisotropy, the mass percentage of the compound of the general formula III is 3% to 28%, preferably 5% to 26%, and more preferably 7% to 25%.

[0046] Preferably, the compound having the structure of the general formula VI is selected from one or more of the following compounds VI-1 to VI-32:

[0047]

[0048]

[0049]

[0050]

[0051] More preferably, the compound represented by the general formula IV is selected from one or more of the compounds IV-2, IV-3, IV-4, IV-5, IV-6, IV-8, IV-10, IV-14, IV-16, IV-20, IV-22, IV-25, and IV-27.

[0052] In the liquid crystal composition having positive dielectric anisotropy, the mass percentage of the compound of the general formula IV is 25% to 75%, preferably 27% to 70%, and more preferably 30% to 68%.

[0053] Preferably, the compound having the structure of the general formula V is selected from one or more of the following compounds V-1 to V-25:

[0054]

[0055]

[0056] More preferably, the compound represented by the general formula V is selected from one or two of the compounds V-6 and V-23.

[0057] In the liquid crystal composition having positive dielectric anisotropy, the mass percentage of the compound of the general formula V is 3% to 30%, preferably 5% to 29%, and more preferably 6% to 27%.

[0058] The liquid crystal composition having positive dielectric anisotropy further comprises one or more additives selected from one or more of antioxidants, UV stabilizers, and chiral dopants, and the content of the additives is 0 to 0.5% of the total mass of the liquid crystal composition.

[0059] The liquid crystal composition having positive dielectric anisotropy comprises the following components in mass percentages:

[0060] (1) 1 to 15% of the compound represented by general formula I;

[0061] (2) 5 to 28% of the compound represented by general formula II;

[0062] (3) 3 to 28% of the compound represented by general formula III;

[0063] (4) 25 to 75% of the compound represented by general formula IV;

[0064] (5) 3 to 30% of the compound represented by general formula V.

[0065] Preferably, the liquid crystal composition having positive dielectric anisotropy comprises components in the following mass percentages:

[0066] (1) 1 to 13% of the compound represented by general formula I;

[0067] (2) 7 to 25% of the compound represented by general formula II;

[0068] (3) 5 to 26% of the compound represented by general formula III;

[0069] (4) 27 to 70% of the compound represented by general formula IV;

[0070] (5) 5 to 29% of the compound represented by general formula V.

[0071] More preferably, the liquid crystal composition having positive dielectric anisotropy comprises components in the following mass percentages:

[0072] (1) 1 to 12% of the compound represented by general formula I;

[0073] (2) 8 to 23% of the compound represented by general formula II;

[0074] (3) 7 to 25% of the compound represented by general formula III;

[0075] (4) 30 to 68% of the compound represented by general formula IV;

[0076] (5) 6 to 27% of the compound represented by general formula V.

[0077] Still more preferably, the liquid crystal composition having positive dielectric anisotropy comprises components in the following mass percentages:

[0078] (1) 2 to 10% of the compound represented by general formula I;

[0079] (2) 9 to 20% of the compound represented by general formula II;

[0080] (3) 8 to 23% of the compound represented by the general formula III;

[0081] (4) 35 to 65% of the compound represented by the general formula IV;

[0082] (5) 8 to 25% of the compound represented by the general formula V.

[0083] The liquid crystal composition with positive dielectric anisotropy of the present invention can be used in liquid crystal displays, including TN mode, FFS mode, and IPS mode displays.

[0084] The liquid crystal composition with positive dielectric anisotropy of the present invention has characteristics of a relatively high clearing point, appropriate optical anisotropy, large positive dielectric anisotropy, low threshold voltage, and a large ε⊥ / Δε ratio, and can be applied to TN mode, FFS mode, and IPS mode displays. The liquid crystal composition provided by the present invention can enable the liquid crystal display device to achieve low-voltage driving, making it more energy-saving. At the same time, this composition has a large ε⊥ / Δε ratio, which is beneficial to improving the transmittance of the liquid crystal display.

[0085] Advantages of the present invention:

[0086] The liquid crystal material with positive dielectric anisotropy provided by the present invention has a relatively high clearing point, appropriate optical anisotropy, large positive dielectric anisotropy, low threshold voltage, and a large ε⊥ / Δε ratio, which can enable the liquid crystal display to achieve low-voltage driving while also improving the transmittance of the liquid crystal display. It is applicable to TN mode, FFS mode, and IPS mode displays.

[0087] The liquid crystal composition provided by the present invention has a relatively high clearing point, appropriate optical anisotropy, large positive dielectric anisotropy, low threshold voltage, and a large ε⊥ / Δε ratio. In particular, the large dielectric anisotropy and low threshold voltage are beneficial to reducing the driving voltage of the liquid crystal display, thereby making it more energy-saving; at the same time, this composition has a large ε⊥ / Δε ratio, which is beneficial to improving the transmittance of the liquid crystal display.

[0088] The liquid crystal composition with positive dielectric anisotropy provided by the present invention can enable the liquid crystal display to achieve low-voltage driving, making it more energy-saving. At the same time, this composition also has a large ε⊥ / Δε ratio, which is beneficial to improving the transmittance of the liquid crystal display. Detailed implementation manners

[0089] The abbreviated codes for the test items in the following examples are as follows:

[0090] Tni: Clearing point;

[0091] no: Refractive index of ordinary light (589 nm, 25 °C);

[0092] ne: Refractive index of extraordinary light (589 nm, 25 °C);

[0093] Δn: Refractive index anisotropy (589 nm, 25 °C);

[0094] Δε: Dielectric anisotropy (1 kHz, 25 °C);

[0095] wherein, Δε = ε∥ - ε⊥, where ε∥ is the dielectric constant parallel to the molecular axis, and ε⊥ is the dielectric constant perpendicular to the molecular axis, test conditions: 25 °C, 1 kHz;

[0096] V 10 : Represents the threshold voltage measured at 25 °C;

[0097] V 90 : Represents the saturation voltage measured at 25 °C.

[0098] In the following examples, the group structures in the liquid crystal compounds are represented by the codes shown in Table 1.

[0099] Table 1 Functional group codes of liquid crystal compounds

[0100]

[0101]

[0102] Taking the following compound structure as an example:

[0103]

[0104] Functional group code representation: 3APUQUF

[0105]

[0106] Functional group code representation: 3PGUQUF

[0107]

[0108] Functional group code representation: 5CCPGF

[0109]

[0110] Functional group code representation: 3CPO1

[0111] Weigh the compounds with the corresponding general formula structures according to the mass percentages in the examples. Place the weighed monomers in a hard high-borosilicate glass bottle. Under nitrogen protection, raise the temperature and stir with electromagnetic stirring or mechanical stirring until a molten, clear, homogeneous, and transparent solution is obtained. Then continue stirring for 30 minutes to thoroughly and evenly mix the materials, and then stop heating. Carry out degassing under reduced pressure while stirring; as the temperature decreases, the vacuum degree increases. When the temperature cools down to room temperature, stop stirring and continue evacuating until no bubbles are seen. Then it can be poured into the test box for testing.

[0112] Taking Example 3 as an example, the preparation method of the liquid crystal compounds in the embodiments of the present invention will be described below. The preparation steps of other examples are the same as this.

[0113] Weigh 5% of the compound of general formula I-2, 10% of the compound of general formula II-6, 5% of the compound of general formula II-10, 13% of the compound of general formula III-6, 3% of the compound of general formula III-8, 8% of the compound of general formula IV-2, 8% of the compound of general formula IV-3, 8% of the compound of general formula IV-4, 8% of the compound of general formula IV-5, 9% of the compound of general formula IV-6, 3% of the compound of general formula IV-14, 3% of the compound of general formula IV-16, 14% of the compound of general formula V-6, and 3% of the compound of general formula V-23 according to the mass percentages in Example 3. Place the above-mentioned weighed monomers in a hard high-borosilicate glass bottle. Under nitrogen protection, raise the temperature and stir with electromagnetic stirring or mechanical stirring until a molten, clear, homogeneous, and transparent solution is obtained. Then continue stirring for 30 minutes to thoroughly and evenly mix the materials, and then stop heating. Carry out degassing under reduced pressure while stirring; as the temperature decreases, the vacuum degree increases. When the temperature cools down to room temperature, stop stirring and continue evacuating until no bubbles are seen. Then it can be poured into the test box for testing.

[0114] Table 2 Composition and test data of the liquid crystal composition in Example 1

[0115]

[0116] Table 3 Composition and test data of the liquid crystal composition in Example 2

[0117]

[0118]

[0119] Table 4 Composition and test data of the liquid crystal composition in Example 3

[0120]

[0121]

[0122] Table 5 Composition and test data of the liquid crystal composition in Example 4

[0123]

[0124] Table 6 Composition and Test Data of Liquid Crystal Composition of Example 5

[0125]

[0126]

[0127] Table 7 Composition and Test Data of Liquid Crystal Composition of Comparative Example 1

[0128]

[0129] Table 8 Composition and Test Data of Liquid Crystal Composition of Comparative Example 2

[0130]

[0131]

[0132] Table 9 Composition and Test Data of Liquid Crystal Composition of Comparative Example 3

[0133]

[0134]

[0135] The parameters of the liquid crystal compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were summarized and compared, as shown in Table 10.

[0136] Table 10 Performance Comparison of Liquid Crystal Compositions in Examples 1 to 5 and Comparative Examples 1 to 3

[0137] Tni (°C) Δn Δε ε⊥ / Δε V10 V90 Example 1 97.7 0.0976 9.38 0.40 1.08 2.01 Example 2 92.8 0.1043 9.89 0.39 1.07 1.92 Example 3 94.0 0.1028 10.32 0.38 1.06 1.91 Example 4 103.1 0.1414 9.29 0.39 1.65 2.36 Example 5 109.4 0.1513 10.05 0.37 1.78 2.56 Comparative Example 1 90.8 0.1237 10.64 0.36 1.27 2.07 Comparative Example 2 90.1 0.1017 11.10 0.36 0.98 1.79 Comparative Example 3 94.7 0.1085 10.45 0.36 1.10 1.90

[0138] As can be seen from the above table, the compounds of General Formula I were added in Examples 1 to 5, not added in Comparative Example 1, 3DGUQUF was used to replace the compound shown in General Formula I in Comparative Example 2, and 3CPUQUF was used to replace the compound shown in General Formula I in Comparative Example 3. The ε⊥ / Δε ratios of Comparative Examples 1 to 3 were all 0.36, and the ε⊥ / Δε ratios in Examples 1 to 5 were 3% to 11% larger than those in Comparative Examples 1 to 3. When this liquid crystal composition is applied in TN mode, FFS mode, and IPS mode displays, it is beneficial to improve the transmittance of liquid crystal displays.

[0139] The liquid crystal composition provided by the present invention has a high clearing point, appropriate optical anisotropy, large positive dielectric anisotropy, low threshold voltage, and a large ε⊥ / Δε ratio. In particular, the large dielectric anisotropy and low threshold voltage are beneficial to reducing the driving voltage of the liquid crystal display, thereby making it more energy-efficient; at the same time, the composition has a large ε⊥ / Δε ratio, which is beneficial to improving the transmittance of the liquid crystal display.

Claims

1. A liquid crystal composition having positive dielectric anisotropy, characterized in that: According to mass percentage, it contains: (1) at least one compound of the structure represented by general formula I, with a mass fraction of 1% to 15%, wherein the general formula I is: In the formula, R1 represents a C1-C7 alkyl group or a C1-C7 alkoxy group; (2) at least one compound of the structure represented by general formula II, with a mass fraction of 5% to 28%, wherein general formula II is: In the formula, R2 represents a C1-C7 alkyl group or a C1-C7 alkoxy group; n1 represents 0 or 1; ring ring and ring Independent Representatives: wherein one or more H on the benzene ring may be replaced by F; (3) at least one compound of the structure represented by general formula III, with a mass fraction of 3% to 28%, wherein the general formula III is: In the formula, R3 represents a C1-C7 alkyl group, a C1-C7 alkoxy group or a C2-C7 straight-chain alkenyl group; X1 and X2 are the same or different and each independently represents -H or -F; (4) at least one compound of the structure represented by the general formula IV, the mass percentage of which is 25% to 75%, the general formula IV being: In the formula, R4 and R5 each independently represent a C1-C7 straight-chain alkyl group, a C1-C7 straight-chain alkoxy group, a C2-C7 straight-chain alkenyl group or -F; X3 and X4 independently represent -H and -F; ring and ring Independent Representatives: wherein one or more H on the benzene ring may be replaced by F; (5) at least one compound of the structure represented by general formula V, the mass percentage of which is 3% to 30%, wherein general formula V is: In the formula, R6 and R7 each independently represent a C1-C7 straight-chain alkyl group, a C1-C7 straight-chain alkoxy group, a C2-C7 straight-chain alkenyl group or -F; ring express: One or more H on the benzene ring may be substituted by F.

2. The liquid crystal composition having positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by the general formula I is selected from one or more of compounds I-1 to I-4:

3. The liquid crystal composition having positive dielectric anisotropy according to claim 1, characterized in that: The compound of the structure shown in general formula II is selected from one or more of compounds II-1 to II-12:

4. The liquid crystal composition having positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by the general formula III is selected from one or more of compounds III-1 to III-8:

5. The liquid crystal composition having positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by the general formula VI is selected from one or more of compounds VI-1 to VI-32:

6. The liquid crystal composition having positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by the general formula V is selected from one or more of compounds V-1 to V-25:

7. The liquid crystal composition having positive dielectric anisotropy according to claim 1, characterized in that: The liquid crystal composition with positive dielectric anisotropy further comprises one or more additives, wherein the additives are selected from antioxidants, UV stabilizers and / or chiral dopants, and the content of the additives is 0 to 0.5% of the total mass of the liquid crystal composition.

8. The liquid crystal composition with positive dielectric anisotropy according to any one of claims 2 to 6, characterized in that: The compound represented by general formula I is compound I-2; the compound represented by general formula ⅠI is selected from one or more of compounds ⅠI-6, ⅠI-10 and ⅠI-11; The compound represented by the general formula ⅢⅠ is selected from one or two of compounds ⅢⅠ-6 and ⅢⅠ-8; the compound represented by the general formula ⅠⅤ is selected from one or more of compounds ⅠⅤ-2, ⅠⅤ-3, ⅠⅤ-4, ⅠⅤ-5, ⅠⅤ-6, ⅠⅤ-8, ⅠⅤ-10, ⅠⅤ-14, ⅠⅤ-16, ⅠⅤ-20, ⅠⅤ-22, ⅠⅤ-25 and ⅠⅤ-27; the compound represented by the general formula V is selected from one or two of compounds V-6 and V-23.

9. A liquid crystal display, characterized in that: A liquid crystal composition having positive dielectric anisotropy comprising the liquid crystal composition according to any one of claims 1 to 8.

10. The liquid crystal display according to claim 9, characterized in that: The liquid crystal display includes TN mode, FFS mode and IPS mode displays.

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